Process for stabilizing a petroleum oil



Oct. 3o, 1945.

G. E. PHILLIPS PROCESS FOR STABILIZING PETROLEUM OILS Filed sept. 14. 194s desirable degree.

peraturewithin the desired operating range, var-` -ferred temperature.

Patented Oct. 3 0, 1945 N UNITED STATES VPA'rlaN'r OFFICE Gerald E. Phillips, Cranford, N. J., assignor to Standard Oil Development Company, a corporation of Delaware Application September 14, 1943, Serial No. 502,235

4 Claims.

It is known in the art to subject various pei troleum oil feed stocks, such as heavy naphthas,

gas oils, reduced crudes and the like, to temperature `and pressure conditions adapted to pro-' duce relatively lower boiling constituents and relatively higherboiling constituents. It is also known in the art to refine the `resulting'products `by` treating the samewith various clays, metallic oxides and' the `like for the purpose of Astabilizing the saine and particularly for the pur# pose of removing objectionable'unsaturated material by polymerization. For example, a cracked motor fuel product may beimproved by contacting the same with an 'activated clay catalyst at elevated temperatures.' whereby the dioleiins present may be removed by polymerization. Gasolines may be treated by such a method in order to improve color and reduce the tendency to form gum.

A diiilculty which arises in connection with the treatment of materials containing unsaturated compounds with anactivated clay catalyst at elevated temperatures is the fact that after the reaction has been initiated the large quantity of exothermic heat evolved causes the temperature of the catalyst bed to rise to an un- In order to control the temious proposals have been made. It has been proposed that the feed stock be introduced into the clay treating zone somewhat below the pre- When operating in` this manner, a portion of the exothermic heat is taken up by the feed stock and degradation of the feed stock is prevented. It has also been proposed to utilize various cooling means, such as cooling coils and the like, throughout the reaction zone. This, however, has not been en-K tirely satisfactory owing to the fact that in order adequately and positively to control the temperature of the reaction, the reaction zone must have a relatively small diameter.

I have now discovered a process by which it is Ypossible to positively control the temperature of the reaction throughout the reaction zone but a F. Ito 450 F., in a case where incoming feed stock within the desired critical temperature range. In accordance with my process the temperature within the treating zone is maintained substantially constant by partially deactivating the clay catalyst after the reaction has been well initiated,` by introducing at a plurality of points Within the catalyst bed small amounts of water, either as liquid water or steam. It will be understood that the catalytic activity of the clay is dependent on the removal of most of the combined water by burning at quite high temperatu'res. It has been found that the maximum activity of a vtypical Attapulgus clay can be reached by heating the clay at a temperature oi S-1000* F., but when heating at somewhat lower temperatures, e. g., 500 F., the clay shows no appreciable activity. The control of the water content of the clay is therefore an extremely important feature in the control of the activity of the clay as a catalyst. It has therefore beenl found possibleto partially deactivate the clay catalyst during the treating process in order that reaction may become much less violent and the temperature controlled within the desired` range.

By introducing only relatively small amounts of water into the catalyst bed the temperature control by partial deactivation of the catalyst is brought about. The amount of water necessaryis far less than that which would be required for simple cooling by contact. It has been found, for example, that in order to reduce the temperature of a reaction of the type desired from 535 is-at a temperature of 375 F., about 4% of water, based on the feed stock, would be required if the water effected the desired reduction in temperature by simple contact, and that if it was desired to reduce the temperature to 375 F. the amount of water required would be from 8% to 10%, depending on the temperature of thewater. However, by acting as an agent for deactivating clay the amount actually required to reduce the temperature through a drop of 200 F. or less would be about 0.1%, based on the feed stock, and about 0.5% if the water is in the form of steam.

The process of my invention may be readily understood by reference to the attached drawing illustrating a preferred emebodiment of the same. For purposes of illustration, it is assumed that the feed oil comprises a cracked petroleum distillate boiling in the motor fuell boiling range, such as a severely cracked gasoline of 400 F. end p oint containing substantial quantities of conjugated diolens. 'I'he feed oil is introduced into the heating coil I by means of feed line 2 and is raised to the desired temperature, e. g., a

temperature of about 375 F. The feed oil is ample, in the form of wet steam, are introduced at a plurality of points by means yof `line 5, which branches into lines 6, 1, and' 8, respectively, lead`- ing directly into the reaction zone. By means of thermocouples 9, I0, and Il the amount. of water or steam introduced into the` catalystbed m-ay'bev automatically controlled in conformity with variations in the temperature of. thefbed.v The treated, oil withdrawn from reaction zone 4 by means of line l2 may be further handled or refined in any manner desired. It is torbe. understood thatl clay treating zone 4 may comprise any suitable num.- berV and arrangements of contacting units.. In a .processsueh as that herein, `described the pres sure employed maybe. any pressure. required to maintain the treated oil substantially in liquid phase, and in the. specic. example. described. a-

suitable pressure is. about 100l lbs/sq.. in. gauge. Itfmay notbef necessary in many cases to. continue. adding water during the entire. process; ofi operation, since the. claymay become suiiciently deactivated after a certain period of. time-to maintain thertemperature .the desired limits for the.I remainder of the operation.

rlhe process of the present.l invention may` be, adaptedl to they treatment of. any mineral. oil. with activated clay in Whichthe-reactionis exotl'iemnicA andA in whicltit. is desired to control the. temperature within a. narrow critical temperature` range. As. stated ab.ove, thei-nvention. is particularly applicable inthe treatment of motor fuelfractions containing unsaturated material, such as that produced by severe thermal or catalytic cracking. ci. light and heaviI naphthas. and. gas oils under low pressure to 200 pounds/sq. in. gauge) and high temperature (e950 to. 1400.9 F.) conditions either with or without, the. presence of steam.. Such, stocks. usually have A.. S. T. M. acid heats in thef range of 100 to50.0 F. and diene numbers` oi5to40. I

In. operations: of the type described in. which polymerizationof the. unsaturated; portionsof. the: feedstock takes place, itis desirable thatA the tem--A perature in the reaction zone be controlled: inthe rangeirom. about300 to alaoutettl.o F.. The oper-- ation, ingeneral, is conducted under substantially non-cracking conditions.

The; cooling fluid added. at aplurality of stages-e comprises Water in the liquid or vaporouse state;- and. wet steam, such as a. typical refinery exhaustl steam at about lbs. pressure. and at aI temperatlrre1 of abouty 267 F., is particularly suited for the purpose. In general, it has been found preferable to introduce the water at at least three stages and to introduce not more than about 0.2% of liquid Water or 1.0% of steam by Weight, based upon the feed oil. Particularly desirable results aresecured by utilizing a plurality of thermostats or .equivalent means in the path of the flowing lluid immediatelypreced`1ng`the respective points of introduction into the reaction Zone', in a manner adapted to regulate and control the inward `flow of the deactivating fluid.

The clay used` as a catalyst in the processes `described may be any adsorptive clay suitable for preparing active catalysts, such as Attapulgus cl'ay, fioriti-in, fullers earth and the like. In general; it is preferred' that the clay be activated by burning` the same at a temperature in the range from about. 950 to abcut'lOOOo F. A desirable particle size is from 30 to 60 mesh.

In general, the most desirable feed rate for the incoming oil stockY should. be from. 0:.1'tov 1.0 vol u'mes' per volume-*of `clay in. the catalyst, Kbed per.v hour, and preferably fromabout 0-.2-5 tosa'bout 1.0. volume: per volumaof clay per hour.

The present invention isy notto be considered as limited by any of the examples or embodiments thereof, which are.- describedherein.v for illustrative: purposes only,l but is limited solely by the terms of the appended-claims.

1. A process for stabilizing a. petroleum .oil-r 'fractiona of essentially the motor: ffuel range and containing a substantialquantity of unsaturated compounds, whichcornprises contacting-the saine in liquid phase with-a bedof an activated clay catalyst at a temperature at leastashtgh ass'f F; and .controlling the` temperature Within'. vvthe reactionzone byv introducing Water inta .ther'lcatai` lyst.y bedat a plurality of andi only am amount Whicha is not. more than about 1=f%.,.

on they feed stock.

2; Aprocessv as definedv in claim 1. inwhi'ehx .tire temperature of. the feed stockintroducertihtoi the reaction zone is not.'higherthan .4100 F.; Y 3; A process for-stabilizing.apetroleum oilslaction of thev motor 'ueh range contairn'ng;substan-A tial quantitiesfof dielens; whi'cix comprises1 conitacting. thesa-me in liqiud. phase:A with a bed; ci am activated clay catalyst at a temperature oi about 300 to about 450 F; and controlling theftemperaturewithin thev reaction zone introducing noty rigori th-anabout. 1% of. steam, rbased` onathey feed? s oc i n 4v.. A processas defined' im claim. 3 in which-fthe*- steamis introduced'. atzat least three points withinthe catalyst. bed and. in which. the amount of steam introduced at each: point isA thermostati callycontrolled sov that the temperature the-catalyst bed iszmainta-ined at from about 3009 to-about450 F.

Ea. PESIILLIEBPSaV` 

